Supernova Remnant VRO 42.05.01

ROSAT PSPC image
(from Burrows and Guo, ApJ, 421, L19, 1994 ) of the
galactic supernova remnant (SNR) VRO 42.05.01 (also known by its galactic
coordinates as G166.0+4.3). The ROSAT image, shown in false color
representation, includes X-rays between about 0.5 keV and 2 keV which
are believed to be produced by emission from hot gas (T ~ 8.5 million
degrees Celsius) in the interior of the supernova remnant. The radio
continuum image shown in the inset (from Dr. T. Landecker of the Dominion
Radio Astronomy Observatory) is overlaid on the X-ray image as contour
lines, showing that X-ray emission fills the interior of the radio shell,
although the SNR looks very different at these two wavelengths. The radio
image has a typical edge-brightened appearance, while the X-ray image is
brightest in the interior and relatively faint at the edges. The intensity
profile along the line shown in green, which roughly bisects the SNR along
its symmetry axis, is shown in red along the bottom of the image, and has a
very sharp peak in intensity in the white portion of the color image. This
bright spot may be due to increased X-ray emission as the shock wave from
the supernova explosion devours an interstellar cloud. The peculiar morphology
of this SNR is believed to result from the eruption of a spherical SNR (the
upper left portion) into a region of very low density. The SNR then expanded
rapidly into this low density cavity in the interstellar medium, producing
the larger "wing" component in the lower right-hand half of the image.

This work was done by
Dr. David Burrows and graduate student Zhiyu Guo of the Penn
State Department of Astronomy and Astrophysics.